Investigation 2

There are three states of matter: solid, liquid, gas.

A solid is matter that has a definite volume and a definite shape. A solid can be turned or moved or placed in different containers, but its volume and shape stay the same.

A liquid is a matter that has a definite volume, but no definite shape. A liquid poured from one container to another container takes up the same amount of space. But, the shape of the liquid changes. A liquid has the same shape of the container.

A gas is a matter that has no definite volume and no definite shape. Like a liquid, a gas takes the shape of its container. However, a gas will spread out to fill every part of a container.

Matter in each state is made of very tiny particles. Any one of these particles is much too small to feel, taste, smell, or see. The smallest particle of matter is called an atom. How small is an atom? The period at the end of this sentence could contain more than 2 billion atoms! Atoms are always moving. The way they move depends on the state of the matter. Atoms move the least in solids and move the most in gases.

Matter can change in two ways: through a physical change or through a chemical change.

A physical change is a change in the size, shape, or state of matter. When you boil water, you will notice bubbles forming in the water and rising to the surface. The bubbles were water vapor, a gas. At the surface, the bubbles burst, sending the water into the air as a gas. When the water changes from a liquid to a gas, this is a physical change. When a physical change happens, no new matter is made. Water is still water, whether it's a liquid or it's a gas.

A chemical change is a change in matter in which different kinds of matter are formed. Remember the campfire? When the wood changed into smoke and ashes, a chemical change has happened. Smoke and ashes are the new matter that were made, and we no longer has any wood. The wood cannot be brought back because a chemical change has changed it into something new.